Apparatus for folding web material



Aug. 10, 1965 c. w. PRESNELL ETAL 3, ,8

APPARATUS FOR FOLDING WEB MATERIAL 5 Sheets-Sheet 1 Filed April 10, 1961INVENTORS. CHARLES W. PRESNELL WALTER A. SCHUH BY ATTOZNEY Aug. 10, 1965c. w. PRESNELL ETAL 3,199,861 APPARATUS FOR FOLDING WEB MATERIAL FiledApril 10, 1961 5 Sheets-Sheet 2 INVENTORS.

CHARLES w. PRESNELL Tmve' WALTER A. SCHUH ATTORNEY c. w. PRESNELL ETAL3,199,861

APPARATUS FOR FOLDING WEB MATERIAL Aug. 10, 1965 5 Sheets-Sheet 3 FiledApril 10. 1961 INVENTORS. CHARLES W. PRESNELL WALTER A. SCHUH ATTORNEYAug. 10, 1965 c. w. PRESNELL ETAL 3,199,861

APPARATUS FOR FOLDING WEB MATERIAL 5 Sheets-Sheet 4 Filed April 10, 1961INVENTORS.

CHARLES W. PRESNELL WALTER A. SCHUH ATTORNEY Aug. 10, 1965 c. w.PRESNELL ETAL 3,199,861 APPARATUS FOR FOLDING WEB MATERIAL Filed April10, 1961 5 Sheets-Sheet 5 I81 78 i9 X 73 INVENTORS. CHARLES W. PRESNELLWALTER A. SCHUH *3 By 5/ F7 24 5551111111 M ATTORNEY United StatesPatent 3,199,361 APPARATUS FUR FULIDING WEE MATERIAL Charles W.Presnell, Media, and Waiter A. Schnh, Lansdowne, Pa, assignors to ScottPaper Company, Philadeiphia, Pa., a corporation of Pennsylvania FiledApr. 10, 1961, Ser. No. 101,757 8 Claims. (Ci. 279-40) This inventionrelates to improved apparatus for folding webs of flexible material andmore particularly for producing stacks of interfolded Webs of suchmaterial.

It is a principal object of this invention to produce in an economicalmanner and at a high rate of production stacks of interfolded webs,particularly webs of fragile, facial tissue and the like.

This invention is related to and constitutes improvements for thegeneral type of web folding apparatus disclosed in Reissue Patent No.21,785 to P. Burke et al. In the machine of the aforementioned patent, acontinuous stack of folded tissure paper is formed on a moving conveyorby successively laying onto a moving conveyor webs of material which arefolded as they are drawn from a plurality of parent rolls carried in amultiple spindle backstand. The moving stack of folded webs is severedat appropriate intervals to produce conveniently sized, individualstacks of folded sheets. The principal advantage of this machine overprior machines has been its ability to produce stacks of folded webmaterial at high production rates.

Many present day brands of facial tissues, paper towels, and the likeare packaged with portions of adjacent sheets interleaved, orinterfolded, in such a manner that with drawal of the top-most orouter-most sheet causes a portion of the next sheet to be drawn throughthe delivery opening of the package Where it is readily accessible tothe user. Naturally, attempts have been made to produce such interfoldedproducts on a continuous basis, i.e., in the general manner of themachine described in the aforementioned Burke patent. To our knowledgehowever, such attempts have not been entirely successful in producingeither a machine or a method which is both economical and reliable. Thisis particularly true with respect to methods and machines forinterfolding webs of facial tissue which, because of their extremelyfragile nature, are difficult to handle and fold without wrinkling ortearing. Prior attempts to produce machinery for interfolding facialtissue webs have resulted in large and complicated machines which arecostly, and diflicult and expensive to maintain and operate.

A principal feature of this invention is that a multipleroll machine forproducing interfolded webs and embodying the invention occupiessubstantially no more floor space than a similar machine adapted forproducing noninterfolded stacks of webs, although the folding operationsperformed on the latter machine are considerably less extensive thanthose required for producing interfolded stacks.

In certain prior machines in which a stack of folded webs is formed on amoving conveyor it has been the practice to provide a folding orinterfolding device at the conveyor for each web that is to be added to,or connected to, the moving stack. Inasmuch as it is seldom economicalto market stacks of fewer than 100 sheets, such machines have had 100 ormore folding, or joining, stations along their conveyors with the resultthat the machines occupied an undesirable amount of floor space. Inaccordance with the present invention, certain pairs or sets of webs fedto the stack conveyor are preliminarily folded and interfolded away fromthe immediate vicinity of the stack conveyor. A reduced number of finalinterfold stations are thus required at the conveyor and these are ofimproved design capable of handling pairs or sets of preliminarilyinterfolded webs. In this manner, the overall length of j hfihi PatentedAug. 10, 1965 "ice the conveyor is held to a minimum, the length of thema chine is minimized and, consequently, the amount of floor spaceoccupied by the machine is held to a minimum.

Another problem encountered in operating prior machines for producinginterfolded webs has to do with threading webs from newly placed parentrolls through the several folding devices which are required to impartthe desired folds to the Webs. Such threading operations areparticularly complicated in a machine for producing interfolded websbecause not all of the webs are folded to the same hand. In other words,certain webs must possess right-hand folds and adjacent webs mustpossess left-hand folds in order for the webs to interleave in properrelationship in the finished stack.

Another important object of this invention, therefore, is thesimplification of the web threading operation in multi-web foldingequipment. This objective is accomplished by a novel arrangement anddesign for the several folding devices employed in the machine, wherebysuch devices are accessibly located and conveniently presented to thetender of the machine for threading purposes.

A further object of the invention is the interfolding of multiple websof fragile facial tissue without wrinkling, tearing, or breaking any ofthe webs.

A still further object of the invention is the provision of improvedfolding devices capable of alternatively folding one or both edgeportions of webs conveyed thereover to render the machine capable ofproducing variously folded webs and of producing interfolded andnon-interfolded stacks of webs.

These and other objects, advantages, and features of the invention willbe apparent from the following detailed description of the invention inwhich reference is made to a preferred embodiment thereof illustrated inthe accompanying drawings, wherein:

FIGURE 1 is a front elevational view of apparatus for folding andassembling webs of flexible material in accordance with this invention;

FIGURE 2 is a perspective view of a plurality of webs as they appear inmoving through the apparatus of FIG- URE 1;

FIGURE 3 is a diagrammatic view illustrating certain folding andinter-folding steps performed by the apparatus of FIGURE 1;

FIGURE 4 is an enlarged, side elevational view of a folding deviceemployed in the apparatus of FIGURE 1 and which is capable of foldingone or both longitudinal edges of a moving web;

FIGURE 5 is an elevational view of the web face of the folding deviceshown in FIGURE 4;

FIGURE 6 is a view similar to FIGURE 5 but on a reduced scale andshowing a folding device of opposite hand;

FIGURE 7 is a rear elevational vieW of the folding device of FIGURE 4,but showing the components thereof in different positions by whichanother type of web fold is produced;

FIGURE 8 is a fragmentary, three-quarter rear perspective view of thefolding device of FIGURE 4 illustrating the manner in which a web ofmaterial passes thereover;

FIGURE 9 is a transverse sectional view of the folded web leaving thefolding device of FIGURE 8;

FIGURE 10 is a view similar to FIGURE 8, but showing the components ofthe folding device in position to produce a C-fold in the Web passingthereover;

FIGURE 11 is a transverse sectional view through the web leaving thefolding device of FIGURE 10;

FIGURE 12 is a front elevational view of another folding device employedin the apparatus of FIGURE 1;

FIGURE 13 is an elevational view of the web face of the folding deviceof FIGURE 12;

. lurality of parent rolls 32 of web material. 31 includes a pluralityof arbors, or spindles, 33, preferover its folding devices and 39.

ings.

FIGURES 14 through 16 are views illustrating the manner in which thefolding device of FIGURE 12 assembles two moving webs of material,FIGURE being a sectional view taken as indicated by line I5-15 in FIGURE14;

FIGURE 17 is a plan view of an interfolding device employed in theaparatus of FIGURE 1;

FIGURE 18 is a front elevational view of the interfolding device ofFIGURE 17;

FIGURE 19 is a vertical section through the interfolding device taken asindicated by line 19-19 in FIG- URE 17;

FIGURE 20 is a fragmentary perspective view from above, illustrating themanner in which Web is folded in passing through the folding device ofFIGURES 17-19.

FIGURE 21 is a perspective view from below of the web shown in FIGURE20;

FIGURE 22 is a view similar to FIGURE 20, but illustrating the manner inwhich the interfolding device assembles a pair of webs to a moving stackof interfolded webs;

FIGURE 23 is a transverse sectional view taken generally as indicated byline 2323 of FIGURE 22;

FIGURE 24 is a diagrammatical illustration of the -web formation shownin FIGURE 23;

FIGURE 25 is an enlarged elevational view of a conveyor supportingdevice employed in the apparatus of FIGURE 1.

Referring particularly to FIGURE 1, the apparatus there illustratedconstitutes a portion only of a machine for producing stacks ofinterfolded webs of material, such as webs of facial tissue, papertoweling, etc. Although it is the general practice to market facialtissues or the like in packages of 100 or more sheets and machines forproducing such packages normally handle a plurality of webs equal innumber to the number of sheets desired, or more, the principles of thepresent invention can be readily understood from an examination of but aportion of such a machine. The appartus shown in FIG- URE 1 comprises astand 31, sometimes referred to as a backstand, which functions toprovide support for a The stand stand 31. The four webs from each stackof parent rolls 52 meet at another guide roller 37 before passing into.a lower, folding and assembling region of the machine. Positionedwithin this region of the machine are a plurality of folding devices oftwo types, designated and 39 respectively. Folding devices 38 and 3%have individual webs 34 guided thereto by further guide rollers 48'.

Each web 34 receives a preliminary fold in passing For convenience inidentifying this folding operation and the fold produced thereby,reference numeral I is employed in the draw- The precise nature of foldI is described herein after.

Preceding downwardly from folding devices 33 and 39 the webs areconveyed over suitable guide rollers 41, are directed into pairs anddirected to a further set of folding devices, each of which isidentified generally by numeral 42. .A preliminary interfold, identifiedas fold II, is

.performed on each pair of webs moving over folding device 42. Thepie-interfolded pairs of webs thereafter pass through pairs of pressrollers into a set of final interfold devices 44, which are seriallyarranged along a moving conveyor 46. One or both rollers of each pair ofrollers 43 may be driven for the purpose of drawing webs 34 over andthrough folding devices 38, 35, and 22.

Each pair of webs passing through a final interfolding device 44- has afold, identified as III, performed thereon which assembles that pair ofwebs in interfolded relationship with a moving stack of interfolded webs47 carried on conveyor 46. Conveyor 46 is driven by any suitable sourceof motive power, such as an electric motor, and functions to convey theassembled stack of interfolded webs to a severing device (not shown) bywhich individual, package-sized stacks are obtained. Conveyor 46 alsofunctions to draw the Webs through folding devices Movement of theconveyor 46 may be either continuous or intermittent, as desired.

The above constitutes a brief description of the major components of theapparatus embodying the invention. The method of folding andinterfolding webs contemplated by the invention and the steps involvedin the method can be best ascertained by reference to FIGURES Zand 3 ofthe drawing, which diagrammatically display the folding operationsperformed on the webs passing through the apparatus. Continuous websprogressively being subjected to operations to produce folds I, II, andIII are illustrated in FIGURE 2. FIGURE 3 contains diagrammaticillustrations of cross sections of the web folds in four webs, i.e., thenumber of webs fed from a single stack of four parent rolls 32 (see FIG.1). For convenience, the four webs are identified as A, B, C, and D.

The folding method includes imparting fold I to each of webs A, B, C,and D by which one longitudinal edge portion of each web is folded backonto a contiguous portion of the web. This fold usually is described asa J-fold because when represented diagrammatically, as

shown in FIGURE 3, the folded web resembles the letter I. It will benoted that alternate ones of the webs are oppositely folded. A and C,for example, which pass over folding devices 38, have imparted theretoright-hand folds While webs B and D, which pass over folding devices 39,have left-hand folds imparted thereto. Oppositely folded pairs of websare next assembled in superposed relationship with unfolded edgeportions of each web projecting beyond the folded edge of the other webof the pair (see web pair A and B and web pair C and D in FIGURE 3). Thepairs of webs are then preliminarily interfolded by means of fold II(produced by folding devices 42) whereby a longitudinal edge portion ofweb B is folded about the previously folded edge of web A and alongitudinal edge portion of web D is folded about the previously foldededge of web C. Here it will be noted that webs B and D are given foldsof the same hand and, consequently, all folding devices 42 may beidentical. The web pairs are thus prepared for assembly to the movingstack of interfolded webs 47 on conveyor 46.

Sequential assembly of web pairs is effected by fold III, whereby thelower-most web of each pair, webs A and C, have their previouslyunfolded edge portions folded about an edge of the top-most web on themoving stack 47. As depicted by the dotted-line arrows (FIG- URE 3)indicating conveyor travel, web pair A-B, when assembled to the movingstack, receives the subsequent web pair C-D as fold III is applied tothe unfolded edge of web C causing it to wrap around an edge of web Bbetween webs A and B. It should be noted at this point that all of thefinal interfolds III are of the same hand; in other words, web A isfolded in the same direction to join it to the moving stack 47 as is webC in joining the latter web pair to web B. As will appear in greaterdetail hereinafter, this is important because it enables all of thefinal interfolding devices 44 to be made of the same hand so thatthreading fresh webs through these folding devices is a relativelysimple operation.

While the above description of the folding method in- D volved in thisinvention refers to but four webs from four parent rolls, it can bereadily appreciated that the operations there described, whensuccessively repeated along a conveyor, are capable of building a stackof interfolded tissue of virtually unlimited size. The method can bepracticed on a machine having 100 or more parent rolls on but one facethereof. A similar set of rolls and folding evices may, if desired, beprovided on the opposite, or back, face of the machine to double thecapacity of the machine.

It will be noted from the lower-most characters in FIGURE 3 that thefully folded webs treated in the above described method have anS-configuration in cross section. This configuration is particularlybeneficial for boxed, interfolded facial tissues because the edge foldon the exposed portion of the top-most web constitutes a convenientfinger gripping region and facilitates dispensing individual sheets. Itcan be readily appreciated, however, that the basic principles of thisimproved method of interfolding can be practiced in the production of,so called, Z-fold inteifolded sheets and in the production of simpleV-fold interfolded sheets. In the latter practice the initial edgefolds, folds I, are not required and these folds are simply omitted byremoving or bypassing folding devices 33 and 39.

The remaining figures of the drawings illustrate in detail theconstruction and function of each of the folding devices employed in theapparatus of FIGURE 1. Folding devices 38 and 3? illustrated in FIGURESand 6, respectively, are employed to impart fold I to the webs and,consequently, are employed in aggregate number equal to the number ofwebs to be handled by the machine. Folding devices 38 and 39 are similarbut of opposite hand. The form of device illustrated in FIGURES 4 and 5may be designated as being right-hand and has its components arranged toproduce a longitudinal fold along the front edge of a web passingthereover, i.e., the edge of the web presented to one viewing theapparatus as it appears in FIGURE 1. The folding device in FIGURE 6 hasits components arranged to produce a similar fold along the rear, orback, edge of a web passing thereover, and can be designated as beingleft-hand.

Folding device 38 comprises a guide plate 51 adapted to have a webtrained over the face thereof. The plate 51 has a relatively wideentrance portion 52 which is angularly dispose with respect to andconverges into a narrower tail portion 53. Obliquely disposed withrespect to the tail portion 53 of plate 51 and positioned in closelyspace relationship with the back face of this plate portion is a fixedlymounted guide rod 54. Rod 54 is adapted to guide one edge of a web 34around the adjacent edge or" plate 51 to produce a fold in the web inthe manner illustrated in FIGURE 8. It will be noted that a web 3 passedthrough folding device 38 is bent on a transverse line in its passagefrom the entry portion 52 to the tail portion 53 of guide plate 51. Thisbending of the web enables an edge portion of the web to be deflected tothe inside of the bend out of the plane of the remaining portions of theweb. This bending of the web permits the edge of the web to be foldedcompletely within but a short travel distance of the web withoutstretching or otherwise unduly stressing the material from which the webis made. The angular relationships between the components of foldingdevice 38 are maintained such that the web portion being foldedtraverses the same distance in short-cutting the bend and moving to itsfolded position as do other portions of the web which are not folded.Because all portions of the web passing through device 38 traverse thesame distance, there is no tendency for one portion of the web to bestretched or wrinkled with respect to another portion of the web.

The bend-fold principle of web folding just described is employedthroughout the several folding devices of this invention in the interestof conserving space occupied by the folding devices and of insuringgentle handling of the webs. This latter consideration is ofconsiderable importance in apparatus designed to handle fragile tissuewebs, which have very low tensile strength. The bendfold principle isconsidered preferable to certain other types of known folding deviceswherein portion of the webs are gently urged or coaxed into foldedrelationship as the web traverses an extended linear or near linear pathof travel. These other folding device occupy considerable space, therebygreatly increasing the size of multiple web handling machines and alsodo not handle the webs with the same dexterity as the folding devices ofthe present invention.

The folding devices of FIGURES 4 through 8, i.e., both forms 38 and 39,possess another feature, namely convertibility, which renders thedevices capable of folding both longitudinal edges of a web to aconventional C- fold configuration (see FIGURE 11). This feature stemsfrom incorporation of certain movably adjustable components into thefolding device. As shown in FIGURES 4- through 7, folding devices 38 and39 include a movable guide plate section, or extension, 56 which isadapted to be disposed in coplanar relationship with the edge of guideplate 51 which is opposite the location of fixed guide rod 54. Guideplate extension 56 appears on the right in the right-hand folding device38 illustrated in FIGURE 5 and appears on the left in the left-handfolding device 39 illustrated in FIGURE 6.

Extension 56 of guide plate 51 is mounted for swinging movement on atube 57 which supports folding device 38 on the machine frame 31.Extension 56 further includes a detent, indicated generally at 58, whichis capable of maintaining the extension in the position illustrated inFIGURES 4 and 5 in which the extension provides support for that edge ofthe web which is opposite the edge being folded (see FIGURE 8). A spring5%, also carried by tube 57, biases extension 56 into engagement withits detent 53 but yieldingly permits sliding movement of eX- tension 5ealong tube 57 when it is desired to disengage the extension from itsdetent 58 and move it to an inactive position, such as that illustratedin FIGURE 7.

When guide plate extension 56 is moved to its inactive position,clearance is provided for elevation of a movable guide rod 61, whichcomprises a stationary lower portion 62 and a movable upper portion 63.Movable portion 63 is biased downwardly to an inactive position by aspring 64 when not in use. The inactive position of guide rod 61 isshown in FIGURE 5 and its active, or raised, position is shown in FIGURE7. Movable portion 63 is rotatable with respect to portion 62 toposition a shoulder 65 thereon to engage a should 66 on portion 62 toretain rod 61 in its active position. Manual rotation of portion 63 tomove shoulders 65 and 66 out of alignment permits portion 63 to retractto its inactive position.

The manner in which folding device 33 imparts a C- fold to a web ofmaterial is illustrated in FIGURE 10. It will be noted that both guidebars 54 and 61 are effective in this operation to guide edge portions ofthe Web mtg folded relationship with the remaining portions of the weFold II, by which pairs of webs, such as A and B of FIGURE 3, arepreliminarily interfolded, is performed by folding devices 42, one ofwhich is illustrated in FIG- URES 12 and 13. This folding deviceoperates on the same basic bend-fold principle as the folding devicedescribed previously and includes a guide plate 67 having an entryportion 63 and a tail portion 69. Folding device 4-2 further includes asingle guide bar 71 mounted obliquely adjacent the back face of guideplate 67. Any suitable support such as that indicated at 72 is providedfor mounting folding device 42 on the machine frame SI.

The action of folding device ,2 closely resembles that of folding device38, described previously, with the exception that device 42 receives twowebs in face-to-face relationship and in folding one edge portion of theupper web wraps this edge portion about an edge portion of the lo verweb. The folding action is illustrated in FIG- URES l4, l5 and 16,wherein the two webs are identified as A and B, which designationscorrespond to the design. tions employed in the diagrammatic foldingillustration of FEGURE 3.

The final interfold devices 44 which join a pair of previouslyinterfolded webs to the moving stack of webs 47 on conveyor 46 employ abend-fold principle of fol-ding which differs from that practiced by thepreviously described folding devices. One of the final interfoldingdevices is shown in FIGURES 17, 18, and 19 and its folding action isillustrated in FIGURES 20 through 23. This folding device 44 comprises aframe 73 by which the device is mounted on the machine frame 31. A rearupright face 7a of frame 73 acts as an entry guide surface for the majortransverse portion of the pair of webs entering this folding device.This portion of the web pair turns to a horizontal path of travel abouta tapered roller '76 which is journaled for rotation about a horizontalaxis in frame '73. Roller 76 has been determined to be particularlyeffective for turning the multiple assembly of two prefolde-d webswithout wrinkling the Webs at or near their folds. The folding of onelongitudinal edge of one of the webs passing through the device 44 iseffected by a pan 77 having a guide portion 78 which is slightly obliquewith respect to a line parallel to the direction of travel of themulti-web stack 47, extends upwardly and outwardly from a point near oneend of roller 76 and presents an edge 79, disposed obliquely withrespect to the path of the webs entering the folding device. Theunfolded portion of one of the webs passing through device 44- rnakes aninitial turn about edge 79 of pan 77 (see FIGURES 18 and 29). Pan 77also has a horizontal extension 81 having an edge 82 which is obliquewith respect to the path of travel of the mu'lti-web stack 47. The edgeportion of a web being folded in device ,4 passes around pan edge 7?,follows the rear and lower faces, respectivey, of pan portions 78 and81, bends upwardly about edge 32 into a path parallel to the directionof travel of web stack 47 in folded condition. A portion of the top-mostweb on moving stack 47 is trained over the ripper surface of pan portion81 with the result that the portion of the web being applied to thisstack by folding device 44, and which passes under and around panportion 81, is folded about an edge of this upper-most web on the movingstack. This is illustrated in FIG- URES 23 and 24 in which the two websbeing assembled to the moving stack 47 are identified as A and B,respectively, and the web stack 47 is shown in dotted lines. Web A has apreviously unfolded edge portion folded beneath a portion of thetop-most web on the moving stack 47.

The path of web A through folding device 4-4 is illustratedschematically in FIGURE 21 from which it will be noted that one portion,identified as 33, which is traveling along the underface of pan portion81, is actually moving obliquely with respect to the path of travel ofthe web as it leaves the folding device. This exit path is, of course,parallel to the longitudinal path of movement of stack .-7 on conveyor46. As a consequence of this relationship, portion 83 of web A is movingobliquely with respect to a juxtaposed portion of a web on moving stack47. In order to preclude these relatively moving areas of the two websfrom contacting one another, which contact could produce wrinkling ortearing of one web or the other, folding device 54 is equipped withspacer means in the form of a spacer plate 84 which is secured to thelower face of pan extension 81. Spacer plate 8 is provided with a recess36 in its upper face beneath the region of pan portion 81 over which webA travels. Recess 86 receives portion 33 of the web, as shown in FIGURES19 and 23.

Folding pan '77 of folding device 44 preferably includes an extensioncoplanar with portion 81 to the opposite side of slot 8.2 so that asubstantially flat surface is provided over which the webs travel. Edgeportions of this pan extension 87 are preferably beveled as indicated inFiGURES l7, l9, and 23.

The manner in which a pair of webs, A and B, are directed down ntomoving stack 47 and th previously unfolded edge of web A is foldedbeneath an edge of the top-most web on the stack is sh wn in FIGURE 22.The final configuration of the fully folded and assembled webs isillustrated in FIGURE 24 in which, again, the webs in the moving stackare shown in dotted lines.

it is significant that all pairs of webs entering folding devices haveidentical fold orientation. Thus, all of the final interfolding devices3 are of the same hand and can be threaded from the same side, i.e., thefront face, of the machine. This feature represents a substan tialimprovement over certain prior interfolding machines which were dimcultto thread because the machine tender was required to reach over andbehind certain of the interfolding devices in order to thread in a freshweb of material. Although folding devices 33 and 39, referred topreviously, are of opposite hands, their relatively simple constructionand their open disposition render all of them relatively easy to threadfrom the front face of the machine.

Conveyor 46 preferably takes the form of a flexible belt which isresiliently supported from beneath by suitable means such as thatillustrated in FIGURE 25 on Sheet 1 of the drawings. The supportingmeans shown comprises a roller 91 carried by a bell crank 2, which ispivotally mounted on a shaft 93 and biased in clockwise direction bymeans of a tension pring 94. The construction is such as to urgeconveyor id and such iuterfolded webs as may be contained in the stack47 thereon gently upwardly against a series of rollc s 9-3 whichposition the top of the moving stack with respect to interfolding device44. A lurality of these sp'ing biased support rollers 91 are positionedalong the length of conveyor 46 so as to support it throu hout itslength and permit successive portions of the conveyor to occupyprogressively lower positions and thereby compensate for the growth inthe height of web stack 4-7 toward the exit end of the conveyor. Withthe resiliently supported conveyor of the present invention, allinterfolding devices 44 can be positioned the same distance above ahorizontal reference line, thereby simplifying initial setup andalignment of the machine.

The resiliently supported conveyor 36 of this invention affords theadditional advantage of automatically and continuously compensating forvariations in thickness, or bulk, of the web material handled by themachine. in spite of close quality control, some variation in materialthickness can be expected from various lots of parent rolls. Thesevariations, naturally, result in variations in the thickness of themoving stack 47 during prolonged periods of operations. The resilientlysupported conveyor permit the stack to grow or decrease in heightwithout requiring changes in the positions of folding devices Theprincipal benefits and advantages of this invention can be summarized asfollows: The method practiced, whereby pairs of webs are preliminarilyinterfolded prior to bringing them into assembled relationship withother webs on the conveyor, simplifies the final interfold operationperformed at the conveyor, i.e., reduces the number of individualoperations which must be performed t the conveyor to produce a stack ofany given number of Webs. The apparatus required to practice this novelinterfolding method is of less complexity than prior interfoldingapparatus and employs, to a large extent, relatively simple, easilythreaded, foldin devices. Performance of certain folding andinter-folding operations away from the assembly conveyor of the machineadmits of these folding devices being stacked or pyramided to achievecompactness of the overall machine. Moreover, these advantages areachieved while yet retaining sur'licient versatility of the apparatus topermit it to be converted to the production on non-interfolded stacks ofwebs and of insuring careful handling of the web material during bothconditions of operation.

What We claim is:

1. In apparatus for forming stacks of folded Webs, the combination of aconveyor for a stack of folded webs, a preliminary folding deviceadapted to have a web passed thereover, said folding device beingcapable of alternative- 13/ folding one or both edge portions of the webconveyed thereover, final folding means disposed adjacent the stack ofwebs on said conveyor, said final folding means being adapted uponreceiving a Web having but one folded edge portion to fold the otheredge portion of said web about an edge portion of the top-most Web onsaid stack of Webs and upon receiving a web having both edge portionsfolded of guiding said web onto the top-most web on said stack of webs,and means for adjusting said preliminary folding device to thereby setthe apparatus for the production of a stack of interfolded Webs or theproduction of a stack of non-interfolded Webs.

2. A folding device for interfolding with a longitudinally moving stackof interfolded webs of flexible material another web moving obliquelytoward and onto said stack of webs comprising means for folding andguiding a longitudinal edge portion of said other Web beneath an edgeportion of the top-most web on said stack, said means directing saidother web through a path, at least a portion of which extends obliquelywith respect to the direction of movement of said stack, and spacermeans adjacent said folding means and disposed between said obliquelymoving portion of said other web and the next-to-topmost web in saidstack for preventing contact between said obliquely moving portion ofsaid other web and the nextto topmost web in said stack.

3. In a device for folding longitudinal edge portions of a web conveyedthereover, the combination of a guide plate having entrance and exitportions obliquely disposed with respect to one another, theconstruction and arrangement of said guide plate being such that a webpassing over the convex face thereof executes a bend which is transverseof the web, a turning member positioned adjacent one edge of said guideplate and obliquely disposed with respect to the path of travel of a webover said guide plate, said turning member deflecting a longitudinaledge portion of said web about said one edge of the guide plate, asecond turning member and means supporting said second turning memberfor movement into and away from a position adjacent the opposite edge ofsaid guide plate, said second turning member when positioned adjacentsaid opposite edge of said guide plate being effective to deflectanother longitudinal edge portion of said web to fold other said webportion about said opposite edge of said guide plate.

4. In a device for folding longitudinal edge portions of a web conveyedthereover, the combination of a guide plate having entrance and exitportions obliquely disposed with respect to each other, the constructionand arrangement of said guide plate being such that a web passing overthe convex face thereof executes a bend which is transverse of the web,a turning member positioned adjacent one edge of said guide plate andobliquely disposed with respect to the path of travel of .a web oversaid guide plate, said turning member deflecting a longitudinal edgeportion of said web to fold said web portion about said one edge of theguide plate, a guide plate extension adapted to occupy a positionadjacent the opposite edge of said guide plate, means supporting saidextension and permitting movement of the extension away from said guideplate, a second turning member and means supporting said second turningmember for movement into and away from a position adjacent said oppositeedge of said guide plate in a region occupied by said plate extensionwhen the extension is disposed adjacent said guide plate, said secondturning member when positioned adjacent said opposite edge of said guideplate being effective to deflect another longitudinal edge portion ofsaid web to fold said other web portion about said opposite edge of saidguide plate.

5. In apparatus for folding webs of flexible material to provide amultiple stack of interfolded webs, the combination of an assemblyconveyer, a first set of folding devices spaced from said conveyer, allof said folding devices of said first set being of the same hand, meansfor supplying a pair of webs to each folding device of said first set,each folding device of said first set folding a longitudinal edgeportion of one web of the pair about a longitudinal edge portion of theother web of the pair, and a second set of folding devices arrangedalong said conveyor, all of the folding devices of said second set beingof the same hand and of the hand opposite to said first set of foldingdevices, each of the folding devices of said second set being positionedto receive a prefolded pair of webs from one of the folding devices ofsaid first set, each folding device of said second set including meansfor folding a longitudinal edge portion of the said other web of thepair passing therethrough about a longitudinal edge of a web previouslydirected onto said conveyor.

6. Apparatus as set forth in claim 5 in which said Web supplying meanscomprises a stand and a plurality of rolls of web material carried bysaid stand in stacked relationship above said assembly conveyer andwherein said first set of folding devices are disposed beneath saidrolls and above said conveyer.

7. In apparatus for folding webs of flexible material to provide amultiple stack of interfolded webs, the combination of an assemblyconveyer, a first set of folding devices spaced from said conveyer,means for supplying a web to each folding device of said first set, saidfirst set of folding devices alternately folding opposite edge portionsof successive webs, a second set of folding devices spaced from saidconveyer, each folding device of said second set being positioned toreceive a pair of oppositely folded webs from two of the folding devicesof said first set, all of the folding devices of said second set beingof the same hand, each folding device of said second set folding anunfolded longitudinal edge portion of one web of the pair passingtherethrough over a folded longitudinal edge portion of the other web ofthe pair, and a third set of folding devices arranged along saidconveyer, all of the folding devices of said third set being of the samehand and of the hand opposite to the folding devices of the second set,each folding device of said third set being positioned to receive aprefolded pair of webs from one of the folding devices of said secondset and including means for folding an unfolded longitudinal edgeportion of the said other web of the pair passing therethrough about afolded longitudinal edge of a web previously directed onto saidconveyor.

8. Apparatus as set forth in claim '7 in which said web supplying meanscomprises a stand and a plurality of rolls of web material carried bysaid stand in stacked relationship above said assembly conveyer andwherein said first and second sets of folding devices are disposedbeneath said rolls and above said conveyer.

References Cited by the Examiner UNITED STATES PATENTS 229,479 6/80Scholfield 27094 654,515 7/00 Casterline 270-40 770,508 9/04 Sexton270-40 2,642,279 6/53 Teall I 27040 3,066,932 12/62 Greincr et al.270-40 EUGENE R. CAPOZIO, Primary Examiner.

R. A. LEIGHEY, WILLIAM B. PENN, Examiners.

1. IN APPARATUS FOR FORMING STACKS OF FOLDED WEBS, THE COMBINATION OF ACONVEYOR FOR A STACK OF FOLDED WEBS, A PRELIMINARY FOLDING DEVICE BEINGCAPABLE OF ALTERNATIVE THEREOVER, SAID FOLDING DEVICE BEING CAPABLE OFALTERNATIVELY FOLDING ONE OR BOTH EDGE PORTIONS OF THE WEB CONVEYEDTHEREOVER, FINAL FOLDING MEANS DISPOSED ADJACENT THE STACK OF WEBS ONSAID CONVEYOR, SAID FINAL FOLDING MEANS BEING ADAPTED UPON RECEIVING AWEB HAVING BUT ONE FOLDED EDGE PORTIN TO FOLD THE OTHER EDGE PORTION OFSAID WEB ABOUT AN EDGE PORTION OF THE TOP-MOST WEB ON SAID STACK OF WEBSAND UPON RECEIVING A WEB HAVING BOTH EDGE PORTIONS FOLDED OF GUIDINGSAID WEB ONTO THE TOP-MOST WEB ON SAID STACKD OF WEBS, AND MEANS FORADJUSTING SAID PRELIMINARY FOLDING DEVICE TO THEREBY SET THE APPARTUSFOR THE P OF A STACK OF INTERFOLDED WEBS OR THE PRODUCTION OF A STACK OFNON-INTERFOLDED WEBS.